(a) Field of the Invention
The present invention relates to a socket fixing structure which enables a conductive clamp to be tightly latched and fixed with a conducting plate, so that the conductive clamp will not displace relative to the conducting plate.
(b) Description of the Prior Art
For an ordinary socket, such as an adapter socket, an expansion socket and an extension cord socket, used for an electrical appliance, a circuit of the socket is usually connected with an overload protective device to prevent the circuit from the occurrence of current overload, overheat or fire. When the working temperature of the circuit is too high or the current is too large, the overload protective device can power off by high temperature to keep the safe use of electricity. However, each expansion socket and each extension cord socket are normally provided with plural socket units, wherein one socket unit is used for one plug and plural socket units share one overload protective device. Therefore, once the overload protective device powers off, all the socket units will power off, which will cause inconvenience in use. In addition, when all the socket units power off, a user is not able to know clearly which socket unit is in trouble, and even the user does know the socket unit that results in power-off, he or she will not be able to know whether it is due to the malfunction of the conductive clamp of the socket unit or it is due to the short circuit caused by the malfunction of the electrical appliance itself. Therefore, it is not very ideal to use these conventional socket units.
Accordingly, the present inventor has applied for a Taiwanese utility model patent publication No. M477079, “Overheat Failure Safety Structure, and a Socket and a Plug with the Overheat Failure Safety Structure,” on Apr. 21, 2014. As shown in FIG. 17, this patent discloses a live wire terminal B which is extended with a live wire spring leaf B1, wherein an open-circuit position that is opened relatively is pre-built between the live wire spring leaf B1 and a live wire copper plate B2, and the live wire spring leaf B1 contacts with the live wire copper plate B2 by a stopper D between the two, thereby forming a closed path position and providing the live wire spring leaf B1 with an elastic restoring force. In addition, a neutral wire terminal C is extended with a neutral wire spring leaf C1, an open-circuit position that is opened relatively is pre-built between the neutral wire spring leaf C1 and a neutral wire copper plate C2, and the neutral wire spring leaf C1 contacts with the neutral wire copper plate C2 by another stopper D between the two, thereby forming a closed path position and providing the neutral wire spring leaf C1 with an elastic restoring force. Moreover, the live wire spring leaf B1 and the neutral wire spring leaf C1 are equipped with an elastic restoring force after bending the material of the spring leaves. This elastic restoring force allows the live wire spring leaf B1 to be opened relative to the live wire copper plate B2 when necessary to form the open-circuit state, and also enables the neutral wire spring leaf C1 to be opened relative to the neutral wire copper plate C2 when necessary to form the open-circuit state.
As the live wire copper plate B2 contacts with the live wire spring leaf B1 sufficiently by the tight clipping of the stopper D, and the neutral wire copper plate C2 also contacts with the neutral wire spring leaf C1 sufficiently by the tight clipping of another stopper D, the effect of electric conduction is good to reduce effectively the temperature resulted from turning on the current at that contact location. When any socket in the extension cord socket E is subjected to current overload, short circuit or circuit overheat, the working temperature at the contact location between the live wire copper plate B2 and the live wire spring leaf B1 or between the neutral wire copper plate C2 and the neutral wire spring leaf C1 will reach to the thermal deformation temperature (such as 120° C.), allowing the two stoppers D to be deformed and damaged by the thermal deformation temperature. At this time, the live wire spring leaf B1 will displace away from the live wire copper plate B2 by the abovementioned elastic restoring force, or the neutral wire spring leaf C1 will displace away from the neutral wire copper plate C2 by the abovementioned elastic restoring force, changing the contact location from the closed path position to the open-circuit position to stop supplying the current and prevent the working temperature from ascending continuously. As the two stoppers D are made of a non-conductive material, when the two stoppers D are deformed and damaged or even fractured into two parts by heat, the damaged stoppers D will never cause short circuit by contacting with peripheral electronic elements accidentally, so that the implementation can be safer.
The abovementioned conventional overheat failure safety structure can achieve the function of allowing the conductive clamps (i.e., the live wire terminal B and the neutral wire terminal C) of a receptacle of each socket unit to power off, without interfering with the normal power supply of the receptacles of other socket units. However, as the two conductive clamps are inserted by the pins of a plug, if there is no good fixing structure, the two conductive clamps can easily displace upon pulling or inserting the pins of the plug, allowing the contact surface between the two conductive clamps to result in sloshing, which can easily cause the stoppers D to get loose. Therefore, the improvement is needed.